Many of the bolded characters in the characterization above are apomorphies of subsets of streptophytes along the lineage leading to the embryophytes, not apomorphies of crown-group embryophytes per se.

All groups below are crown groups, nearly all are extant. Characters mentioned are those of the immediate common ancestor of the group, [] contains explanatory material, () features common in clade, exact status unclear.

Evolution. Possible apomorphies for flowering plants are in bold. The actual level at which many of these features, particularly the more cryptic ones, should be assigned
is unclear. This is because some taxa basal to the [magnoliid + monocot + eudicot] group have been surprisingly little studied, there is considerable homoplasy as well as variation within and between families of the ANITA grade in particular for several of these characters, and also because details of relationships among gymnosperms will affect the level at which some of these characters are pegged. For example, if reticulate-perforate pollen is optimized to the next node on the tree (see Friis et al. 2009 for a discussion), it effectively makes the pollen morphology of the common ancestor of all angiosperms ambiguous... For other features such as a nucellus only one (Nymphaeales) to three cells thick above the embryo sac and a stylar canal lacking an epidermal layer, although plesiomorphous for basal grade angiosperms (Williams 2009), where on the tree a thicker nucellus and a stylar epidermal layer are acquired has not yet been indicated.

Tricolpate pollen has been found in the Late Barremian-Early Aptian of the Cretaceous some 127-120 m.y.a., and so a minimum age of some 125 m.y. for the eudicots is reasonable (e.g. Magallón et al. 1999; Sanderson & Doyle 2001; Friis et al. 2011 for numerous references), an age that is also similar to that of the oldest monocot fossils. However, as Smith et al. (2010) note, when tricolpate pollen first appears in the fossil record it is both widely dispersed geographically and quite heterogeneous (see also Friis et al. 2006b). This would imply an earlier origin of the clade, the fossils then being more marks of its "rise to dominance" than of its origin (Beaulieu et al. 2013: p. 4).

The recent discovery of Leefructus, dated to at least 122.6 m.y. old and assigned to stem group Ranunculaceae (Sun et al. 2011; c.f. Crepet et al. 2004 for an earlier mesofossil estimate), would also imply a substantially greater age for Ranunculales - and hence the whole eudicot clade - of ca 152-140 m.y. (age extrapolated from the ages of various clades in Ranunculales given by Anderson et al. [2005]). Although Leefructus seems quite well preserved, it is not associated with pollen (Sun et al. 2011). Friis et al. (2011) discuss a variety of early fossils that are, or from general morphology might be, associated with tricolpate grains.

Evolution.Divergence & Distribution. In the topology found by Zhang et al. (2014) there is a substantial period of 16-26 m.y. (ca 35 m.y. in Zhang et al., but c.f. suppl. Table 6) between the divergence of [Ceratophyllales + Chloranthales] and the eudicots. Subsequent divergence of eudicot clades like Proteales, Buxales, etc., may have been rapid, occurring 120-116 m.y.a. (Anderson et al. 2005), while Wikström et al. (2001) thought that the clades immediately below core eudicots had diverged by (140-)135, 123(-118) m.y. ago.

Cuticle waxes as clustered tubules, nonacosan-10-ol the
main wax, could be optimised to this position, later being lost in Sabiaceae, Platanaceae, Buxales, and perhaps also in core eudicots (such waxes are present in a few Santalales, also in woody Saxifragales: see Barthlott et al. 2003). Doyle (2007) scored chloranthoid teeth as plesiomorphous for eudicots; given current ideas of phylogeny, they may be an apomorphy here. He also considered palmate-crowded veins to be an apomorphy for all eudicots, but Sabiaceae were not mentioned, and the interpretation of the venation of Euptelea is debatable, as he noted (Doyle 2007). The palmate venation in aquatics like Nelumbo may further confuse the situation; palmate venation is common in aquatics with their broad peltate or cordate-based leaf blades and so is associated with the aquatic life style.

For a valuable survey of floral morphology of the whole eudicot clade, see Endress (2010c); "a first [sic] attempt to characterize the major subclades of eudicots", including other than "conventional features" (ibid. p. 540); characterizations are a mixture or apomorphies and plesiomorphies, with an emphasis on "tendencies". For the evolution of syncarpy, see Sokoloff et al. (2013d).

Dimerous flowers are to be found in the basal eudicot grade, but are at most very uncommon in taxa at the node above core eudicots and in monocots (Drinnan et al. 1994; Soltis et al. 2003; Wanntorp & Soltis et al. 2005; Ronse De Craene 2005; Doust & Stevens 2005; Kramer & Zimmer 2006; Moody & Les 2007; Doyle 2013; such flowers are found in the core eudicot Haloragaceae); Endress (2010c) also emphasized that the flowers may be trimerous. Stamens are also quite often inserted opposite the tepals in the basal eudicot grade, even if there is more than a single whorl of tepals (e.g. see Endress 1995a for illustrations of these in Ranunculales; Doust & Stevens 2005). This feature is placed at the [monocots [Ceratophyllales + eudicots]] node here, but the flowers of Lauraceae (magnoliids) are similar.

Taxa with androecia that are initiated as antesepalous triplets are scattered throughout the group (Hufford 2001a), although they are rather uncommon. Although stamen number may be high, development is rarely simply centripetal, as in Magnoliales (e.g. Corner 1946b), and carpel and perianth/petal number do not often increase in parallel, unlike in the euasterids. The basic pollen type for eudicots seems to be tectate/semitectate-reticulate, the latter grains being found in e.g. Platanacaeae, Menispermacaeae, Hamamelidaceae, Gunneraceae (Denk & Tekleva 2006) and Nelumbonaceae. For optimisation of syncarpy in this part of the tree, see Sokoloff et al. (2013d).

Ecology & Physiology. Liu et al. (2014) suggest that it is only with the eudicots that we see generally faster litter decomposition with all its implications in terms of nutrient cycling.

Pollination Biology. Diversification of eudicots is roughly contemporaneous with that of bees; the latter is estimated to have begun (132-)123(-113) m.y.a. (Cardinal & Danforth 2013). Protandry is common in eudicots, although aquatic taxa tend to be protogynous, and protogyny is also common in mono- and dioecious taxa (interfloral protogyny: see Bertin & Newman 1993).

For the possible functional significance of the evolution of triaperturate pollen, see e.g. Dajoz et al. (1991), Halbritter and Hesse (2004), and Furness and Rudall (2004); the occurrence of several apertures on one grain may increase the speed of germination of the pollen, but at the same time decrease its viability and affect its harmomegathic movements. For pollen aperture development, see Banks et al. (2010).

Genes & Genomes. Salse et al. (2009) suggested that the common ancestor of this clade had seven chromosomes. Taxa in which GLO-like proteins cannot form heterodimers predominate in this clade (Melzer et al. 2014); DEF-like proteins also cannot do this (see also the [monocot + eudicot] node). Melzer et al. (2014) also suggest that this may contribute to the increasing canalization of floral development.

Chemistry, Morphology, etc. See Hegnauer (1990) for a discussion of the chemistry of the old grade group Polycarpicae, which includes many Ranunculales, the magnoliids and Austrobaileyales. The Eudicot Evolutionary Research website should also be consulted.

Phylogeny. Ranunculales are usually sister to all other eudicots, and Ceratophyllaceae may be sister to eudicots (e.g. Moore et al. 2007); see also the discussion at the mesangiosperm node. The position of Chloranthales, magnoliids, Ceratophyllales and monocots, all somewhere immediately basal to the eudicots, still remains unclear.

There is also still uncertainty about basal eudicot relationships. An unresolved Proteales and Sabiaceae are often sister to eudicots minus Ranunculales (e.g. S. Kim et al. 2004b). A position [Ranunculaceae [Sabiaceae [all other eudicots]]] had only 83% support, of which most came from the matK gene (the other genes examined were petD and trnL-F) in analyses by Worberg et al. (2006, 2007); for this topology, see also Qiu et al. (2010: support weak). A three-gene analysis by Soltis et al. (2003) also found that that Sabiaceae were near Proteales, Buxales, etc., while Morton (2011: nuclear Xdh gene) found some support for a [Platanaceae + Ranunculales] clade and a four gene analysis (Kim et al. 2004a) had a weakly supported [Trochodendrales [Sabiaceae + Buxales]] clade. Moore et al. (2008) did not find strongly-supported relationships in this part of the tree, and various permutations of relationships of the groups being discussed, none strongly supported, were found by Zhu et al. (2007). Soltis et al. (2008) used the topology [Proteaceae [Sabiaceae [Buxaceae [Trochodendraceae + core eudicots]]]] in their book (see also Goloboff et al. 2009; Fiz-Palacios et al. 2011 for other relationships).

However, Proteales and Sabiaceae are sister taxa in an analysis of all 79 protein-coding plastid genes and four mitochondrial genes (Moore et al. 2008: support only moderate; see also Soltis et al. 2011 and Moore et al. 2011: support weak in both cases). The two were also sister in the major analyses of chloroplast and nuclear data in Sun et al. (2014), but not in the mitochondrial study and in many of the supplementary trees. Savolainen et al. (2000a), Qiu et al. (2006b, c.f. 2010), Burleigh et al. (2009), N. Zhang et al. (2012); Ruhfel et al. (2014: not all analyses), Z. Wu et al. (2014), and Magallón et al. (2015) have also found (weak) evidence for an association of Sabiaceae with Proteales, and so an expanded Proteales is recognised here. Morphology is consistent with such a position.

The relationships of Buxales and Trochodendrales are also unclear. Although Worberg et al. (2007) found that Buxales were sister to core eudicots in most analyses, relationships in this general area were scrambled using the PetD marker alone. Qiu et al. (2006b) also found uncertain relationships in a three-gene analysis of mitochondrial data, but with eight genes a topology similar to that used in the Summary Tree was found (see also Qiu et al. 2010). Hilu et al. (2003) also suggested that Buxales were sister to core eudicots. Worberg et al. (2006, 2007) presented a 3-gene (chloroplast) phylogenetic analysis focussing on the eudicots; most of the relationships they found along the eudicot spine were strongly (>90% jacknife) supported. Soltis et al. (2011) in their seventeen-gene analysis found strong support for the relationships along the basal spine of the eudicots shown here (see also Moore et al. 2010; Xue et al. 2012; Vekemans et al. 2012; Ruhfel et al. 2014; Z. Wu et al. 2014; Magallón et al. 2015). The positions of Buxales and Trochodendrales was reversed in the study by Wikström et al. (2003; see also Moore et al. 2011 for position of Buxales and Trochodendrales).

Magallón et al. (1999) suggested a fossil-based age of ca 70 m.y. for the clade, but the fossil was a member of the decidedly non-basal Menispermaceae. The crown group age suggested by Early Cretaceous fossils from Portugal can perhaps be assigned to this part of the tree - or to Berberidopsidales or Saxifragales (von Balthazar et al. 2005). The recent discovery of a fossil assigned to stem group Ranunculaceae (see below) that is at least 122.6 m.y. old (Sun et al. 2011) implies a decidedly greater age for the clade, perhaps 152-140 m.y. or so extrapolating from the suggestions of Anderson et al. (2005). If its identity is confirmed, all age estimates in the order may well have to be revised upwards.

Krassilov and Volynets (2008) discuss a number of fossils from the Early to Middle Albian (ca 105 m.y.a.) of Primorye that they associated with Ranunculidae sensu Takhtajan, specifically comparing some with Ranunculaceae. The morphology of these fossils is odd, some appearing to have abaxially dehiscent follicles (c.f. Cercidiphyllaceae) and others have axillary fruits at nodes from which branches also arise. The plants are very small, and were described as being weedy (Krassilov & Volynets 2008). The Early Cretaceous Archaefructus has also been compared with Delphinium (Becerra et al. 2012).

Note: Possible apomorphies are in bold. However, the actual level at which many of these features, particularly the more cryptic ones, should be assigned
is unclear. This is partly because many characters show considerable homoplasy, in addition, basic information for all too many is very incomplete, frequently coming from taxa well embedded in the clade of interest and so making the position of any putative apomorphy uncertain. Then there is the not-so-trivial issue of how ancestral states are reconstructed (see above).

See W. Wang et al. (2009: extensive morphological data matrix) for the evolution of characters optimised on to a tree with the same topology as that used here. Optimization is difficult, for example, where should the character 1-2 ovules/carpel be placed? - low ovule numbers are probably plesiomorphic in the order.

Ecology & Physiology. Liu et al. (2014) suggest that it is only somewhere around this node that the origin of angiosperm leaves with rather fast decomnposability can be pegged.

Pollination Biology. Endress (2010c) emphasized the several independant origins of wind and especially fly pollination in the clade. There are a number of reports of delayed fertilization (up to some two months or more after pollination) in members of Ranunculales, including Eupteleaceae, Circeasteraceae, Lardizabalaceae, and Ranunculaceae (Sogo & Tobe 2006d for references).

Floral nectar spurs have evolved four to six times in Ranunculales; they may be on members of the outer (Myosurus, Delphinium) or inner (Aquilegia) perianth whorls, and be five (Aquilegia), two (Dicentra) or one (Delphinium) in number (Damerval & Nadot 2007).

Genes & Genomes. For the complex pattern of duplication of APETALA3 and FUL-like genes and their expression in Ranunculales, see Sharma et al. (2011) and Pabón-Mora et al. (2012) and references; where to put these duplications on the tree is unclear.

Chemistry, Morphology, etc. See Hegnauer (1990) for a discussion of the chemistry of the Polycarpicae, which also includes the magnoliids and Austrobaileyales. Berberin, common in Ranunculales, is synthesised via the tyrosine pathway. Gleissberg and Kadereit (1999) discussed the evolution of leaf form in the order, with polyternate/acropetal/basipetal-pedate leaves perhaps being plesiomorphic. The glandular leaf teeth have a clear, persistent, swollen cap into which higher order lateral veins also run. What is the distribution of colleters?

There has been considerable discussion over the identity of the different petal/tepal/sepal/stamen parts of the flower in Ranunculales. Almost all Ranunculales, perhaps minus Euptelea, have petals, that is, more or less expanded and attractive parts of the flower (Rasmussen et al. 2009). An inner, more or less petal-like, nectar-secreting whorl is especially obvious in Berberidaceae and Ranuculaceae, and is usually interpreted as being derived from stamens, and Drinnan et al. (1994) suggested that petals had been derived from stamens several times. However, Sharma et al. (2014 and references) found no developmental evidence for a connection between more or less petal-like nectaries and stamens in Ranunculaceae, at least.

This next paragraph to be reworked: Gene expression patterns in the inner perianth whorl of Ranunculaceae and Berberidaceae are unique, and intermediates can be explained by the fading boundaries model of development (ref.). Chanderbali et al. (2010) found that expression of genes active in each floral whorl in flowers of the one member of Ranunculales they examined (Escholtzia) were restricted to that whorl, as in other eudicots; within Ranunculales, Papaveraceae-Papaveroideae, to which Escholtzia belongs, have a perianth that is apparently made up of a rather conventional calyx and corolla. On the other hand, in Delphinium (Ranunculaceae) expression patterns of genes active in the two outer floral whorls were not sharply differentiated (Voelckel et al. 2011). If on occasion I call the outer whorl, "calyx", and the inner whorl, "corolla", it is simply for descriptive purposes.

Monosymmetry has evolved at least twice in this clade, and i>Cycloidea genes are involved. However, they are variously expressed, ad- or abaxially or laterally, in the flower, and may also be expressed in the outer whorl (Jabbour et al. 2014 and references: see Papaveraceae-Fumarioideae and Ranunculaceae below). This is unlike the consistent adaxial expression in Pentapetalae studied (Hileman 2014 and references).

Is the pollen endexine ever lamellate? Antipodal cells are commonly other than simply persistent; data are summarized in Williams and Friedman (2004).

Phylogeny. Relationships in the order are fairly well understood - see Hoot and Crane (1995), Kadereit et al. (1995), Oxelman and Lid&eacuten (1995), Hoot et al. (1999: three genes), Soltis et al. (2011) and especially W. Wang et al. (2009: four genes). Soltis et al. (2003a: four-genes), Kim et al. (2004a), and Worberg et al. (2006, 2007: non-coding chloroplast DNA), all suggest that Eupteleaceae may be sister to the whole of the rest of the order, although support for this position was sometimes only moderate. W. Wang et al. (2009) found a similar position, but support was again only moderate, however, it was strengthened when morphological data were added. Some earlier studies have suggested other topologies, such as Ranunculaceae (Soltis et al. 2000; Hilu et al. 2008 - but no strong support for any position of Eupteleaceae) or Papaveraceae (Soltis et al. 2007a; Anderson et al. 2005; Bell et al. 2010) sister to all other members of the order.

Interestingly, in purely morphological analyses Euptelea was placed well outside Ranunculales, forming a clade with Nelumbo, Illicium, Paeonia, etc. - but mercifully without any bootstrap support (W. Wang et al. 2009); the topology was hightly pectinate, and very few branches had even poor bootstrap support and posterior probabilities were still worse. Loconte et al. (1995) found Ranunculales to be paraphyletic in a morphological phylogeny. Analysis of mitochondrial genes suggested a largely rather different set of relationships between the families (Qiu et al. 2010), although support was mostly (very) weak, only the [Berberidaceae + Ranunculaceae] clade having strong support.

Classification. For a classification of the order, largely followed here, see W. Wang et al. (2009).

Previous Relationships. Papaverales, containing three families (= Papaveraceae below), were commonly recognised as a separate
order next to Ranunculales (Cronquist 1981; Dahlgren 1989), but there is no point in recognising them, especially given that Eupteleaceae appear to be sister to all other families, i.e. including Papaverales.

Eupteleaceae are deciduous trees with short shoots that can be recognised by their spiral, dentate leaves
with strong, ascending, pinnate veins going into the teeth, and excavated petiole bases. The
small flowers lack a perianth, the anthers have a long connective, and the carpels are separate, stipitate and have a stigma like a tooth brush. The fruits are small, disc-shaped samaras down one side of which are the remains of the distinctive stigma.

Evolution.Divergence & Distribution. Anderson et al. (2005) suggested an age of ca 120-111 m.y. for stem-group Eupteleaceae, and Wikström et al. (2001) an age of (141-)135, 122(-116) m.y., but note topologies. Euptelea represents a very old and species-poor clade.

Chemistry, Morphology, etc. Lateral veins only approach the glandular teeth; the gland itself has an apical cavity. Is the wood storied, what about fluorescence, separate bundles?

See Endress (1969, 1993) for some general information, Hegnauer (1973, 1989, 1990) for chemistry, Li and Ren (2005) for wood anatomy, and Ren et al. (2007b) for floral development.

Previous Relationships. Eupteleaceae were placed next to Cercidiphyllaceae in Hamamelidales by Cronquist (1981) or Hamamelididae by Takhtajan (1997). They have been often been linked with Eucommiaceae, for which see Garryales (asterid I).

Age. Magallón et al. (2013) estimated an age of around (404-)394.3-389.9(-382) m.y. for this clade, but it is much younger in most other scenarios; N. Zhang et al. (2012) estimate an age of slightly under 100 m.y., while about 112.9 m.y. is the age in Magallón et al. (2015).

Evolution.Divergence & Distribution. Endress (2011a) suggested that presence of sepals and petals was a key innovation somewhere around here; optimization on the tree is not easy, and it is unclear at what level/for what purpose the sepals and petals of Papaveraceae-Papaveroideae and Ranunculaceae-Ranunculoideae might be considered to be the "same" (see below). For features of wood anatomy common in this part of the clade, see Carlquist and Zona (1988); some may be higher-level apomorphies.

Chemistry, Morphology, etc. Wink (2008) noted that the berberine bridge enzyme (BBE), involved in the synthesis of berberine and other distinctive alkaloids from this clade (Kutchan 1998: berberine is also found in some Rutaceae, etc.) was quite widely distributed in flowering plants. Another gene in this pathway, FAD-dependent (S)-tetrahydroprotoberberine oxidase (STOX), is at least scattered in Ranunculales, and the different forms are quite similar in their activities if with different substrate specificities (Gesell et al 2011). STOX and BBE genes were members of different clades of FAD-dependent oxidases (Gesell et al. 2011).

Papaveraceae are usually herbs with an exudate of some kind whose fleshy leaves have broad bases. The flowers are 2-merous, and the calyx and corolla are clearly distinguishable; the gynoecium has two (or more) carpels, parietal placentation, and usually a short style.

Papaveroideae are usually herbs that may be recognised
by their often soft if rather bristly-hairy leaves, copious latex, and flowers
with two, large, fugaceous sepals enclosing the bud, crumpled petals, usually
numerous stamens, and syncarpous gynoecium with at most a short style and
parietal placentation.

Fumarioideae are often fleshy herbs with watery sap and
distinctive 2-merous mono- or disymmetric flowers that are usually spurred; the calyx is usually very small or almost invisible, certainly not green and enveloping the flower bud, and there are usually six stamens.

Evolution.Divergence & Distribution. Kadereit et al. (2011) discuss evolution within Papavereae, offering some dates. Gleissberg and Kadereit (1999) discuss the complexities of leaf development and interpret them in a phylogenetic context.

Ecology & Physiology. Several species of Fumaria and its relatives are chasmophytes. They grow in the apparently most inhospitable habitats from North Africa and the Mediterranean region eastwards despite their delicate and rather succulent habit.

Pollination Biology & Seed Dispersal. The stigma of Fumaria and relatives, in which the pollen is deposited for secondary pollen presentation, can be complex; there is also secondary pollen presentation in Hypecoum, and here the pollen is deposited on the central lobe of the inner petals. Papaveraceae - Papaver rhoeas, at least - have a fast-acting gametophytic self-incompatibility system which, however, is very different from that in core eudicots (Franklin-Tong & Franklin 2003; Charlesworth et al. 2005).

Quite a number of taxa, both forest herbs and chasmophytes and in both subfamilies, are myrmecochorous, the ants being attracted to the arils developed on the seeds (Fukuhara 1999; Lengyel et al. 2009, 2010); these arils have probably evolved several times.

Economic Importance. For Papaver, see Bernáth (1998).

Chemistry, Morphology, etc. 1-benzyltetrahydroisoquinoline alkaloids are found only here and in a small group of related genera of Rutaceae-Rutoideae, and in Apiaceae and Asteraceae (Kubitzki et al. 2011). Acetylornithine, reported from Fumarioideae, is involved in nitrogen transport (Jensen 1995). The single species in each subfamily examined had distinctive UV fluorescence of unlignified cell walls (Hartley & Harris
1981).

For the unusual (transverse) plane of floral monosymmetry in Fumarioideae, see e.g. Troll (1957), Ronse Decraene and Smets (1992a), Endress (1999), etc.; asymmetry of expression of the CYC gene is in the transverse plane here, and is rather late (Damerval et al. 2013; Hileman 2014). CYCLOIDEA genes have been duplicated in Papaveraceae s.l., and this may be connected with the development of monosymmetry (Kölsch & Gleissberg 2006; Damerval et al. 2007; see Jabbour et al. 2014 for analogous happenings in Ranunculaceae). In Corydalis and some other genera only a single outer
petal is spurred and the flower is monosymmetric; there is a 90° rotation of the flower rather late in development so the spur is in the adaxial position (Ronse Decraene & Smets 1992a) and the monosymmetry is functionally vertical. There is a correlation between flowers with monosymmetry and indeterminate inflorescences, a variant on the correlation of determinate inflorescences and polysymmetric flowers.

Vascularization of the petals of Papaveroideae varies, but even if there is more than a single trace entering the base of the petals, the traces seem to have a single point of origin (Dickson 1935). I am unsure if all/some Papaveroideae have extrorse anthers, but anthers are clearly extrorse in Fumarioideae (Murbeck 1912). As in Ranunculaceae, the numerous stamens in Papaver, etc., may be derived from a paucistemonous condition. The nature of the androecium of Fumarieae in particular has occasioned much discussion, and it has sometimes been suggested that two
anthers have each split into two, monothecal units, so there would be only four stamens altogether, but it is likely that the androecium consists of two dithecal and four monothecal stamens, the dithecal stamens being opposite the outer petals and the monothecal stamens on either side of the insertion of the inner petals (e.g. Brückner 1992; Damerval et al. 2013). In Hypecoum the monothecal stamens have fused in pairs, hence the double vascular supply to two of what appear to be ordinary dithecal stamens (Ronse Decraene &
Smets 1992a for literature). The androecium of Pteridophyllum has also been interpreted as being derived from a flower with six stamens, the lateral stamens having been lost (Ronse Decraene &
Smets 1992a); the dithecal stamens alternate with the petals and are diagonally arranged.

Interestingly, nectary development is associated with the expression of CRABSCLAW genes, unlike the development of nectaries in monocots and Ranunculaceae, but like that in core eudicots (Damerval et al. 2013).

When there are four carpels (mostly Papaveroideae-Papavereae) they are diagonally arranged (Ronse Decraene & Smets 1997b); see Brückner (2000) for discussion of carpel numbers in Fumarioideae. Papaveraceae are described as having hollow styles, although the central space may become occluded by papillae (Hanf 1935). The gametophytic self-incompatibility system of Papaver is associated with a stigma that is dry (Wheeler et al. 2001); Wheeler et al. (2009) suggest that the PrpS gene encoding the pollen S determinant lacks any homologues in other angiosperms that have similar incompatibility systems. The ovary of Fumaria has only a single
ovule and the fruit is nut-like and indehiscent.

For information, see Léger (1895: vegetative morphology and anatomy), Brückner, e.g. 1982 (fruit, mostly Papaveroideae), 1983 (seed, mostly Papaveroideae), 1984 (stigma and carpel, Fumarioideae), 1992 (Pseudofumaria), and 1993 and references (carpels in Fumarioideae), and there is much general information in J. W. Kadereit (1993: as Papaveraceae) and Lidén (1993: as Fumariaceae and Pteridophyllaceae). Some information on Papaveroideae is taken from Dickson (1935: floral vascularization), Sachar (1955), Sachar and Mohan Ram (1958), and Berg (1968), all embryology, Röder (1958) and particularly Meunier (1891) for seed coat anatomy and development, and Ernst (1967: Platystemoneae); see Ronse Decraene and Smets (1990) for floral morphology (comparison with Begoniaceae), and Becker et al. (2005: floral development of Eschscholzia).

For general information about Fumarioideae, see Lidén (1986: esp. Fumarieae), Hegnauer (1969, 1990) and Preininger (1986) for chemistry, Bersillon (1955) for nodal anatomy and floral vasculature, Murbeck (1912) for floral morphology, Guignard (1903) for the embryology of Hypecoum, G. Dahlgren (1981) for stigma secretions, Tarasevich (2014) for pollen, and Fukuhara and
Lidén (1995) for testa anatomy. For ovule
orientation, see Goebel (1932) and Endress (2011b), for style morphology and development, see Kadereit and Erbar (2011). Additional information on Pteridophyllum
is taken from Brückner (1985: fruit and seed); the seeds have a cellulose network in the
endotesta like that of some Papaveroideae.

Pteridophyllum
is particularly poorly known.

Phylogeny. The groupings above are taken from Hoot et al. (1997), Kadereit et al. (1994, 1995) and in particular from W. Wang et al. (2009). Pteridophyllum is apparently rather distinct (although included in Fumariaceae by Cronquist 1981), with its rather harsh pinnate and fern-like leaves; in versions 8 and earlier of this site it was placed as a monotypic subfamily sister to the rest of Papaveraceae. However, W. Wang et al. (2009) found Pteridophyllum to link with Fumarioideae in molecular analyses, although without much support for any particular position, but in total evidence analyses there was strong bootstrap and somewhat less strong posterior probability support for a sister group relationship with Hypecoum in particular. See also Judd et al. (1994) and Nikolic (1995) for earlier studies.

Within Papaveroideae, Papaver is paraphyletic and Meconopsis polyphyletic (Kadereit & Sytsma 1992; Kadereit et al. 1997, 2011; Carolan et al. 2006). For a phylogeny of Fumarioideae, see Lidén et al. (1997); Dicentra is dismembered and the old Corydaleae becomes paraphyletic. In Fumarioideae in particular morphological studies tend to recover a Fumarieae and Corydaleae; for relationships within the former, see Pérez-Gutiérrez et al. (2012).

Classification. A.P.G. II (2003) allows as an option the possibility of including Papaveraceae, Fumariaceae, and Pteridophyllaceae in an expanded Papaveraceae, which I follow here (see also Judd et al. 2002, 2007; Mabberley 2008; A.P.G. III 2009).

Previous Relationships. In some earlier systems, Papaveraceae s.l. were grouped with Brassicaceae, etc., in Parietales, a single-character group characterised by having parietal placentation. Hardly surprisingly, its members are now scattered throughout the tree.

Age. Bell et al. (2010) suggested an age for this node of (106-)92, 85(-71) m.y.; ages of (126-)120, 111(-105) m.y. were suggested by Wikström et al. (2001) and of about 98.2 m.y. by Magallón et al. (2015).

Evolution.Ecology & Physiology. Lardizabalaceae and Menispermaceae are both lianes, sometimes vines, and they both have very large sieve tube plastids. Fossil woods of lianes that can be identified as belonging somewhere in this part of the tree are relatively common in woods Cretaceous-Palaeogene age; woods of Vitaceae-Vitoideae are first known from the Palaeogene (Smith et al. 2013a).

If the evolution of nectaries/nectariferous petals can be placed at this node, details of the pattern of expresssion of AP3-III petal identity genes become interesting (see also Sharma et al. 2011). Nectariferous petals seem not to be staminodial in origin (Sharm et al. 2014). The duplication of Cycloidea genes can be pegged to this node (Jabbour et al. 2014); they are involved in the development of monosymmetric flowers in Ranunculaceae (see below).

Chemistry, Morphology, etc. For the vasculature of the sepals/outer tepals, see Hiepko (1965); for their development, see Zhang et al. (2009 and literature). For pollen morphology, see Nowicke and Skvarla (1982). For chromosome size, see Langlet (1928, 1931) and Okada and Tamura (1979).

Circaeasteraceae are easily recognised. They are small herbs, their leaves have
largely dichotomous venation, and their rather small flowers have separate
carpels.

Chemistry, Morphology, etc.Kingdonia may have up to four bundles departing from the single foliar trace and, like Circaeaster, several root hair zones on the roots (Ren & Hu 1998). Xylem perforation plates may also be scalariform. Kingdonia at least appears to have an adaxial prophyll (see s.e.m. of axillary buds in Ren et al. 2004 - no comment is made about this).

Circaeasteraceae do not show the same relationship between the stamens and perianth members of many other Ranunculales. The perianth members of Kingdonia have a single trifid vein, indeed, all floral organs are innervated by a single vein, apart from the first perianth member, which has two traces (as in some Ranunculaceae, see Ren et al. 2004). The genus also has 8-13 glistening clavate glands immediately inside the perianth whorl; these are described as petals by Tamura (1993) and as staminodes by Ren et al. (2004) and may secrete nectar. Mesogamy, i.e. the pollen tube entering the ovule laterally by penetrating the integument, is reported for Circaeaster, and the mature endosperm is differentiated into two zones; Circaeaster also has endosperm with a chalazal haustorium (see Junell 1931).

General information is taken from Tamura (1993: in Ranunculaceae) and Wu and Kubitzki (1993); see also Nowicke and Skvarla (1981) for pollen, Hu et al. (1990), Ren and Hu (1995) and Tian et al. (2006) for information on Circaeaster agrestis, and Ren et al. (1998, 2004) for information on Kingdonia uniflora. The inside cover of Act. Bot. Bor.-Occid. Sinica 24(1) (2004) has a photograph of K. uniflora flowers with excellent details of gross morphology.

Previous Relationships.Kingdonia has been placed in the Ranunculaceae-Anemoneae, e.g. by Kosuge et al. (1989). The dichotomous venation of the leaves and the separate carpels of Circaeasteraceae have attracted attention as possibly indicating a very "primitive" group.

Kajanthus has receently been described from Portugese Cretaceous deposits around 113 m.y.a. and the charaters available for it are identical to those of Sinofranchetia, so it may even be assignable to crown-group Lardizabalaceae (Mendes et al. 2014).

Lardizabalaceae are usually lianes with compound leaves and broad rays in the wood, the plants being monoecious or dioecious. The flowers are medium-sized and usually six-merous, and
the perianth members and androecium opposite each other. The carpels are free and the fruits are more
or less fleshy, although they are sometimes also follicles.

Chemistry, Morphology, etc. Wood fluorescence? Smets (1986) suggested that the nectaries are staminal nectaries; stamen and petal develop primordia develop immediately adjacent to each other in Holboelllia (X.-H. Zhang & Ren 2011). X.-H. Zhang and Ren (2011) depict dehiscence of the staminodes of Decaisnea insignis; the pollen looks normal (but are there some kind of viscin strands?). Nowicke and Skvarala (1982) studied the pollen morphology especially of Sargentodoxa; there may be additional apomorphies for that genus. The seeds of Akebia, at least, are embedded in some kind of fleshy tissue.

Phylogeny.Sargentodoxa is sister to the rest of the family (Hoot et al. 1995b, see also Hoot 1995a; Kofuji et al. 1994). Decaisnea may be sister to the remainder (Kofuji et al. 1994); it has a number of distinctive (apomorphic) embryological features (H. F. Wang et al. 2009b). However, based on the recent discovery of the fossil Kajanthus, very similar to Sinofranchetia, Mendes et al. (2014) suggest that the root may be misplaced, Sargentodoxa being nested within the crown group.

Classification. Although Sargentodoxa has a number of autapomorphies (see above, also X.-H. Zhang & Ren 2008), there is no compelling reason to segregate it as a family (H.-F. Wang et al. 2009a).

Age. The age of this node may be (119-)113, 103(-97) m.y. (Wikström et al. 2001); on the other hand, Magallón et al. (2013) estimate an age of around 65.9 m.y., Magallón et al. (2015) an age of ca 89.9 m.y., Anderson et al. (2005) an age of 116-105 m.y., Bell et al. (2010) an age of (99-)83, 77(-63) m.y., and Jacques et al. (2011) an age of 125-115.6 m.y..

The scraped stems or roots are yellow in colour in plants that have berberine.

Chemistry, Morphology, etc. For alkaloids found in members of these three families, see Aniszewski (2007). For perianth vasculature, see Hiepko (1964a, b).

Age. Anderson et al. (2005) thought that the crown-group was ca 80-70 m.y.o., Wikström et al. (2001) gave a rather younger age of (59-)53, 48(-42) m.y., while that Bell et al. (2010) at (52-)35, 33(-18) m.y. is even younger. However, Jacques et al. (2011) estimated an age of 124.4-103.3 m.y., while Wang et al. (2012: calibration using Menispermaceae fossils) suggested ages of (115.2-)109.1, 106.3(-101.7) m.y..

Callicrypta, from the mid-Cretaceous of Siberia, has very small flowers (carpellate) with the parts more or less opposite, or forming spirals, and may be Menispermaceae; however, it is unclear what a link between Menispermaceae and Amborellaceae - hardly close - that the fossil is supposed to represent might look like (c.f. Krassilov & Goloneva 2004). Fossils menisperms are reported from the Upper Turonian of ca 89.3 m.y. from the Czech republic and many fossils are known from Lower Ypresian deposits of ca 55.2 m.y. age (Jacques et al. 2011; see also Jacques 2009a). Although Cretaceous records of Menispermaceae seemed questionable to Herrera et al. (2011), Wang et al. (2012) accepted that of Prototinomiscium
vangerowii, from the Turonian of the Czech Republic (Knobloch & Mai 1986; see also Anderson et al. 2005).

Menispermaceae are recognisable by their often
viney/lianescent habit, broad rays, petioles pulvinate at both ends, and often
coriaceous lamina with palmate venation. The lamina is also often peltate, and even if not, the two
sides of the lamina nearly meet on top of the petiole. The plants are dioecious, the often 3-merous
flowers are small, and the drupelets often have a distinctively sculpted
endocarp and can be strongly curved (hence the "moon-seed" family - also Menispermum
canadense).

Evolution.Divergence & Distribution. Major clades within the family diverged during the late Cretaceous (Jacques et al. 2011: Table 5 for dates, Menispermeae sister to rest). Indeed, extensive diversification and migration in the family, which is probably Laurasian in origin, may have occurred around the K/T boundary during a period spanning (82.2-)71.7, 60.3(-45.3) m.y.a. (W. Wang et al. 2012).

South American is proving to be quite diverse in fossils. Doria et al. (2008) found Eocene leaf fossils from northern Colombia, and well preserved endocarps have been recorded from two Palaeocene localities in Colombia, one dated to ca 60 m.y.a. (Herrera et al. 2011); some have been identified as Stephania, now known only from the Old World. If the identification is correct, the younger ages for crown-group Menispermaceae above are incorrect.

For character distributions of fruit and seed that allow their optimization on the tree, see Wefferling et al. (2013); polarization of the variation is not so easy. Hoot et al. (2009) optimized characters on a tree with Menispermum and immediate relatives (Menispermeae) sister to the rest of the family.

Ecology. Menispermaceae are an important component of the climbing vegetation in the tropics, perhaps especially in the New World (Gentry 1991).

Plant-Animal Interactions. Larvae of the large noctuid moths of the subfamily Catocalinae use Menispermaceae as their major food source throughout the tropics, although they can also be found on other plants like Erythrina (some Menispermeae have pentacyclic Erythrina-type alkaloids). The adult moths, with their saw-like proboscides, attack ripe or ripening fruits and cause a considerable amount of damage to commercial crops (Fay 1996).

Economic Importance. The muscle relaxant D-tubocuranine is obtained from Chondrodendrum tomentosum. This is also a major ingredient of the South American poison curare and is put on arrows and darts.

Chemistry, Morphology, etc. There are few records of cork position. Tamaio et al. (2010) did not find serial cambia in the Menispermaceae they examined, but see Tamaio et al. (2009). The tangential cell walls of the rays of Tinomiscium petiolare are oblique to the ray axis when viewed in transverse section; this is uncommon in other Menispermaceae, where the walls are at right angles (Jacques & de Franceschi 2007), but I do not know the distribution of this feature in the outgroups. In at least some Menispermaceae, the presence of laticifers or sclereids is mutually exclusive (Wilkinson 1986). Cocculus has plagiotropic branches (Keller 1996); does it also have two-ranked leaves?

Flowers can be monosymmetric, as in the carpellate flowers of Stephania dielsiana, where there are 1 + 2 or 1 + 3 sepals and petals and a single carpel (W. Wang et al. 2006; Meng et al. 2012); the staminate flowers are always polysymmetric. Tepals in e.g. Menispermum canadense have only a single trace (Smith 1928). There is considerable variation in pollen morphology in the family (Harley & Ferguson 1982 and references) which needs to be integrated with the clades that are becoming evident. The upper of the two ovules is epitropous and fertile, the lower is apotropous (Mauritzon 1936; Joshi 1939). Joshi (1939) suggested that in the unitegmic Tinospora cordifolia, the thinner upper part of the integument represented the outer integument, the thicker part, both integuments fused. There is apparently a period of 6-8 weeks between fertilization and first division of the zygote in Tinospora cordifolia (Sastri 1964). Jacques and Zhou (2010) used Procrustes analyses to understand variation in endocarp morphology; they placed this in the context of a molecular tree.

Additional general information is taken from Réaubourg (1906), Kessler (1993), and Jacques (2006); Hegnauer (1969, 1990) summarized information on chemistry, Wilkinson (1986) described leaf anatomy, and Jacques and de Franceschi (2007), wood anatomy, and Harley (1985 and references) surveyed pollen morphology. Much work has recently been carried out on the complex drupelets of the family; see also Jacques (2009b), Jacques and Zhou (2010), and Ortiz (2012: curved embryos develop in different ways).

Phylogeny. Although Tinomiscium was strongly supported as sister to all other Menispermaceae (Ortiz et al. 2007), the sequences were corrupt (R. Ortiz, pers. comm.). The genus belongs in the [Tinosporeae + Coscinieae] clade, Tinosporoideae, a clade that had at most moderate bootstrap support (Ortiz et al. 2007; see also W. Wang et al. 2009: three chloroplast and one nuclear genes, morphology, support weak, sampling poor; Ortiz 2012). The monophyly of Tinosporoideae was well supported in the analyses described by Wefferling et al. (2013). The tropical Coscinieae are sister to the rest of the subfamily (W. Wang et al. 2012; Wefferling et al. 2013).

Menispermoideae includes the rest of the family and is well supported (but less supported in Wefferling et al. 2013). Within Menispermoideae the temperate Menispermum and relatives (Menispermeae) are sister to the other taxa, again with strong support, and there are other well supported relationships (Ortiz et al. 2007; Wang et al. 2012; Wefferling et al. 2013: c.f. Jacques et al. 2007: morphological data only, variously treated; Jacques & Bertolino 2008, some samples mislabelled, see Jacques et al. 2011). The old Menispermeae, Fibraureae and Peniantheae are polyphyletic (see also Wang et al. 2007a). Hoot et al. (2009: three chloroplast genes) had found that Menispermum and Sinomenium formed a clade sister to all the rest of the family in two gene analyses, but with little support (see also Ahmad et al. 2009; Jacques et al. 2011), although in three-gene analyses they were in a position like that found by Ortiz et al. (2007).

Age. Anderson et al. (2005) suggested an age of ca 104-90 m.y. for this node, Bell et al. (2010) an age of (87-)72, 67(-54) m.y., Xue et al. (2012) an age of ca 77.8 or 89.1 m.y., Magallón et al. (2015) an age of about 80.3 m.y., and Wikström et al. (2001) an age of (106-)100, 84(-78) m.y.; the ca 128 m.y. in Z. Wu et al. (2014) is dramatically older (but see fossils attributed to Ranunculaceae).

Chemistry, Morphology, etc. Nowicke and Skvarla (1981) thought that aperture columellae might be a synapomorphy for the two families. For the expression of the AP3-III gene, see Sharma et al. (2011).

2/601: Berberis (600). General N. temperate,
also South America, N. and E. Africa.

Berberidaceae are herbs or shrubs that may be recognised
by their often yellow-colored secondary tissue (most obvious in the roots) and
their often compound, stipulate leaves with palmate venation and sharply
toothed or spiny margins. The petaloid perianth is often multiseriate, the stamens are often
opposite the perianth members (there are sometimes more), and anther dehiscence may be valvate; there is always a single carpel.

Evolution.Divergence & Distribution. Within the family, Berberis is by far the most widely distributed genus, and fossils have been reported from Palaeocene deposits ca 60 m.y. old in northeast China; Oligocene and younger fossils are known from elsewhere in the Northern Hemisphere (Y.-L. Li et al. 2010). Several genera in Berberidaceae are disjunct and/or occupy only limited areas, and many of the taxa involved may have originated in East Asia. Despite the probably late Cretaceous age of the family, these disjunctions may be relatively recent, forming within the last 10 m.y., although disjunctions in the desert xerophytes Bongardia and Leontice are probably rather older (Donoghue & Smith 2004; Wang et al. 2007b).

Seed Dispersal. Seeds of a number of taxa, both forest herbs and desert xerophytes, have elaiosomes/are arillate (not necessarily different things) and are myrmecochorous (Lengyel et al. 2009, 2010); Berberidoideae in particular have berries.

Bacterial/Fungal Associations. Some seventy species of Berberis (inc. Mahonia) are alternate hosts for Puccinia graminis, the economically very important black stem rust of wheat and other grain crops in Pooideae.

Chemistry, Morphology, etc. In Podophyllum the epidermal waxes are solid rods. The leaves on long shoots of Berberis s. str. are mostly modified as trifid spines that represent leaf blades; there are usually simple but articulated
photosynthetic leaves (i.e. they are unifoliolate) on short shoots, while the scale leaves are basically stipular (Gonzalez & Pabon Mora 2009). Mahonia s. str. (with ca 100 species) has compound leaves, but it hybridises with Berberis.

In Epimedium the nectaries are inside spurs coming from the four inner tepals. Although Podophyllum has many stamens, single stamens or groups of stamens are opposite the innermost perianth members (Schmidt 1928); Zhao et al. (2014) described all floral organs (except the carpel) as originating in whorls of three in the related Dysosma, and, unlike elsewhere in the family, there were no C-A primordia. Ghimire and Heo (2012) described the anther tapetum of Berberidoideae as being glandular; if true, multinucleate tapetal cells would still separate Berberidoideae from other Berberidaceae. Successive microsporogenesis has been reported (Min et al. 1995). The carpel in Berberidaceae varies in its orientation. According to Chapman (1925, c.f. e.g. Feng & Lu 1998), the gynoecium is derived from two or three carpels, with the gynoecia of the n = 6 clade alone being derived from two carpels (Kim & Jansen 1998), however, the gynoecium is probably unicarpellate throughout the family (Brückner 2000 for a summary). Ghimire et al. (2010) described the thinly crassinucellate ovules of Gymnospermium (Podophylloideae) as having a well-developed endothelium. In genera like Caulophyllum the carpel walls do not surround the maturing blue seeds, so the plant is a kind of gymnosperm.

Some general information is taken from Schmidt (1928) and Loconte (1993) and chemistry from Hegnauer (1964, 1989); see Nowicke and Skarvla (1981) for pollen, M.-Y. Zhang et al. (2012) for pollen evolution, and Furness (2008b) for microsporogenesis. Stearn (2002) provides much information on herbaceous Berberidaceae. For floral development of Caulophyllum (with common stamen-nectary primordia), see Brett and Posluszny (1982), for the chaotic arrangement of the androecium in Achlys, see Endress (1989), for spore/gamete development in Diphylleia, see Huang et al. (2010), and for the female gametophyte, see Huss (1906), for that of Podophyllum, see Sreenivasulu et al. (2010).

Phylogeny.Nandina is a very distinctive plant, and in the past it has been segregated as a monotypic family or subfamily (as in versions 7 and earlier of this site). However, Nickol (1995) had suggested on morphological grounds that it was close to Caulophyllum, although placed sister to the rest of the family in the most parsimonious tree that he found. Early molecular studies (e.g. Adachi 1995) found relationships between the two genera, and these have since been confirmed, as by Kim et al. (2004), even if Nandina did sometimes tend to wander about the tree (e.g. Kim & Jansen 1996, 1998). The three groupings above, which more or less form a trichotomy, appear in the analyses carried out by Kim et al. (2004); Podophylloideae have only moderate support (see also Wang et al. 2007b). W. Wang et al. (2009) confirmed these three main clades, and although molecular support for the [Nandinoideae + Berberidoideae] clade was weak, it was much strengthened in analyses that included morphological data.

Nandina: P/K many; nectaries 0; P/K and A develop from the
splitting of a single primordium; pollen with massive endexine; nucellus early absorbed, endothelium ?+; fruit a berrylet; seed concave; endotestal cells crystalliferous, but otherwise testa crushed, endotegmic cells enlarged, lignified, thickened esp. internally, crystalliferous. For floral development, see Feng and Lu (1998); the flower is basically trimerous-whorled, sepals are borne in slightly-spiralling lines up the receptacle, and all perianth parts have ca 3 traces.

Previous Relationships. Fruit dehiscence in some Berberidaceae and Papaveraceae is transverse, at least in part. Although on this account these families are similar (e.g. Endress 1995a), little else indicates immediate phylogenetic relationships.

The recent discovery of Leefructus from early Cretaceous deposits 125.8-122.6 m.y. old in China and assigned to stem Ranunculaceae (Sun et al. 2011) will, if confirmed, very much change our ideas of the evolution of eudicots as a whole.

Age.Paleoactaea, from the Late Palaeocene some 58 m.y.a., has fruits very similar to those of Actaea down to the palisade tissue in the testa (Pigg & deVore 2005). Somewhat older Eocaltha has seeds rather like those of extant Caltha, e.g. both have a flotation chamber. This fossil is from the Mexican Campanian (Cretaceous) some ca 77 m.y. old (Rodríguez de la Rosa et al. 1998; see also Pigg & deVore 2005 for early records), but its identity needs confirmation (Friis et al. 2011).

Ranunculaceae can be recognised by their usually
herbaceous habit; they have spiral, usually exstipulate leaves that are palmately-lobed or have palmate venation and broad
bases. The flowers have large and often
petal-like sepals, variously-shaped nectariferous "petals", spiral, usually numerous
stamens, and separate carpels borne on a well-developed receptacle.

Evolution.Divergence & Distribution.Paleoactaea, from the Late Palaeocene some 58 m.y.a., has fruits very similar to those of Actaea down to the palisade tissue in the testa (Pigg & deVore 2005). Somewhat older Eocaltha has seeds rather like those of extant Caltha, e.g. both have a flotation chamber; this fossil is from the Mexican Campanian (Cretaceous) some ca 77 m.y. old (Rodríguez de la Rosa et al. 1998; see also Pigg & deVore 2005 for early records). If crown-group ages of these fossils is confirmed, they will i.a. constrain the age of the family as a whole.

The beginning of diversification within the speciose Clematis clade has been dated to as recently as (13.1-)7.8(-4.0) m.y.a., however, the stem age is some (43.8-)26(-9.2) m.y. (Mikeda et al. 2006; Xie et al. 2011: HPD).

For the evolution of Arctic Ranunculaceae, see Hoffmann et al. (2010). In the widely-distributed Ranunculus there has been a substantial amount of dispersal in tropical and subtropical mountains and in the Southern Hemisphere - even between southern Africa and America - often followed by radiations (Emadzade et al. 2010, 2011; Hörandl & Emadze 2011). Diversification within Aquilegia (Thalictroideae) has been much studied, the nectar spurs that characterise most of the genus being considered a key innovation that spurred recent and rapid diversification in the clade (Hodges & Arnold 1995 and references). There are only ca 80 species in the clade and they show little molecular differentiation (Whittall et al. 2006).

Delphinium s.l., Aconitum, and relatives (Ranunculoideae-Delphinieae) have monosymmetric flowers and between them account for about a quarter of the diversity in the family. Delphinium s.l. is largely Mediterranean-Turanian in distribution, but with forays into Africa and North America. Delphinieae began diversifying early in the Oligocene (41.8-)32.3(-23.0) m.y.a.; interestingly, the transition from a short-lived (± annual) to a perennial habit in Delphinium is associated with bursts of diversification (Jabbour & Renner 2011, 2012a). There has been duplication of Cycloidea genes involved in this monosymmetry, and they are variously expressed, ad- or abaxially, in the flower, and also in the outer whorl of petaloid sepals (Jabbour et al. 2014; c.f. Hileman 2014).

Expression of a duplicated A-class gene, APETALA 3, is intimately involved in the development of the nectariferous petals found in Delphinieae and many other Ranunculaceae. Absence of the gene has been linked to the loss of the nectarial function, and these nectary-type structures then look much more like the petaloid sepals (R. Zhang et al. 2013; Gonçalves et al. 2013; Sharma et al. 2014).

Pollination Biology & Seed Dispersal. One commonly thinks of Ranunculaceae as having rather unspecialized flowers, and in an analysis of European members of the family Waser et al. (1996) found as many as 53 species of pollinator from 29 genera visiting a single species - and as few as one. Many Ranunculaceae have distinctive nectaries which can be more or less like petals, and some species have complex flowers in which these nectaries take very different forms. Thus Delphinieae have monosymmetric flowers with paired nectary spurs that are borne inside a spurred petaloid member of the outer floral whorl; Renner and Jabbour (2012b) discuss the evolution of this unusual pollination morphology. Bumble bees are the predominant pollinators of the 600-700 species of this tribe, which is very speciose in the Himalayas (Renner & Jabbour 2012b). Diversification of bumble bees, generalist bees that handle specialized flowers quite easily (see below, probably occurred 40-25 m.y.a. (Hines 2008 and references), i.e., about the same time as that of Delphinieae. Rather unusually for a bumble bee, Bombus consobrinus has specialized on Aconitum, especially on A. septentrionale, although several other bumble bees also pollinate members of that genus (Laverty & Plowright 1988; Thostesen & Olesen 1996); Kronfeld (1890: p. 19) early declared Aconitum to be an excellent example of an insect-adapted flower.

The five, coloured nectar spurs of the polysymmetric flowers of Aquilegia are very unusual in flowering plants; nectar spurs are usually associated with monosymmetry. Pollen deposition on the pollinator may be quite precise here (Kay et al. 2006b); Kramer and Hodges (2010) review the evolution of these "petals".

For the intimate association between Old World Trollius and its pollinators/seed parasites, the fly Chiastocheta (close to Botanophila), see
Pellmyr (1992) and Ibanez et al. (2013: plant volatiles). Caltha has nectariferous hairs on the carpels, while taxa like Clematis and Ranunculus have apparently unspecialized flowers and may be visited by many species of pollinators (Waser et al. 1996).

Many species of Thalictrum are wind-pollinated, and some of these species are monoecious or dioecious. Monoecy and dioecy are restricted to and predominate in New World species; wind pollination may reverse to animal pollination (Soza et al. 2012).

A number of forest herbs in Ranunculoideae in particular are myrmecochorous, the outgrowths that attract ants developing either from the seed or the fruit (Lengyel et al. 2009, 2010).

Plant-Animal Interactions. North temperate Ranunculaceae are hosts to over 110 species of dipteran agromyzid leaf miners (Phytomyza: Spencer 1990; see also Jensen 1995), which for the number of species of Ranunculaceae involved may be the most diverse assemblage in flowering plants. Phytomyza (well over 700 species) may have moved on to Ranunculaceae from asterids, perhaps in the late Oligocene ca 24.5 m.y.a., and diversified there as the climate cooled; they have since moved back to asterids, especially to campanulid groups (Winkler et al. 2009).

Genes & Genomes. It is over 80 years since Langlet (1932) realized that the cytological variation in the family has a stong systematic signal, with genera having large R(anunculus)- or small T(halictrum)-type chromosomes, a finding that was at odds with the then-accepted classification. Okada and Tamura (1979) note characters other than gross size and shape that also separate the two chromosome types (see also Tamura 1993). However, the correlation between chromosome morphology and taxonomy does break down; Chung et al. (2013: note lengths given for the two types) found that the chromosomes of some species of Ranunculus like the annual R. sceleratus were quite small, rather like those of the Thalictrum type.

Chemistry, Morphology, etc. Benzylisoquinoline alkaloids are largely absent from Ranunculaceae, although present in Coptis and Isopyyrum (Coptoideae: Jensen 1995), which makes placing this feature on the tree difficult (lost and regained versus two losses). Ruijgrok (1966) clarified the distribution of the lactone ranunculin and of cyanogenic compounds. The vascular bundles often have xylem surrounding the phloem, but c.f. Takhtajan (1997). Clematis, secondarily woody, has
storied wood (see Carlquist 1995a for wood and bark anatomy); it is a liane with opposite leaves with sensitive, twining petioles. There are cortical bundles in the erect stem of Hydrastis, but not in the rhizome; the rhizome of Glaucidium is an irregular sympodium. Variation in petiole anatomy is extensive (Tamura 1962, 1995) and adaxial/intrapetiolar stipules occur sporadically in the family (Hagemann 1970).

Monosymmetry in flowers of Delphinieae becomes apparent only rather late in development after organ initiation (Jabbour et al. 2009a). Soltis et al. (2003a) suggest that both Glaucidium and Hydrastis have a bimerous perianth. Floral phyllotaxy in Anemoneae is particularly variable (Ren et al. 2010).

For an early discussion on stamens and nectaries in Ranunculaceae, and a suggestion that the flower here might be fundamentally 3-merous, see Salisbury (1919). Nectaries in the family vary greatly in morphology, and they were generally thought to be modified stamens. The two have a number of points of similarity, e.g. the "petals" have a single trace, although in some Delphinieae they have two traces (Novikoff & Jabbour 2014). They are in the same parastiches as androecial members, are similar to stamens in early development, are often peltate, originate from a primordium that is a mound rather than a ridge, and there are sometimes intermediates (Jäger 1961; Tamura 1965; Kosuge & Tamura 1989; Erbar et al. 1999; Leins 2000; Zhao et al. 2011; c.f. Kosuge
1994). Normally the nectaries are rather different morphologically from the sepals and are sometimes quite elaborate beaker- or hood-shaped structures; the sepals are more consistently petal-like and visually attractive. However, in Ranunculus and Ficaria sepals are green and protective, while the nectaries are very petal-like, the nectary proper being a small scale at the base of what otherwise appears to be an ordinary petal, while in Laccopetalum and relatives there are a number of nectary ridges on the petals; in the latter both petals and stamens may have three traces (Hiepko 1964a). Pabón-Mora et al. (2013) suggested that aspects of floral development in Aquilegia differed from those in other members of the family. There the basal/abaxial member of alternating staminal rows is a spurred petal/nectary which has three vascular traces running into it. Recent work does not confirm a stamen identity for the nectaries (see above). Genera like Clematis, Thalictrum and Anemone s.l. lack nectaries/petal-like structures inside the petal-like sepals.

In Anemone s.l. the floral bracts/bracteoles
tend to be calycine, and this is especially evident in the Hepatica group where the bracts are borne immediately underneath the flower with its petal-like sepals, although they do not particularly closely envelop the rest of the flower. There the sepals have only a single trace and there are no nectaries. Wang and Chen (2007) discuss "petal" evolution in Thalictroideae; see also above, again, petals/nectaries have been lost. In Aquilegia the stamens are in ten vertically-arranged two-ranked series, each opposite an internal staminode, unique to Ranunculales (see Sharma & Kramer 2012 for their development). Insertion of the stamens, etc., can be spiral or whorled (Gonçalves et al. 2013).

Tamura (1996) described the androecial development of Glaucidium as being centrifugal and the androecium as being innervated by branches of staminal trunk bundles, very like the androecial development common in polystaminate core eudicots. Laccopetalum has huge flowers up to 15 cm across and with ca 10,000 carpels. Although the carpels of Nigella are connate, no compitum is developed (Erbar 1998). There are often five traces to each carpel. When there is only one ovule/carpel, it is
the basal member of the series (c.f. Rosaceae, with which Ranunculaceae
share a superficial similarity, but where the single ovule is the apical member of the series). Uniovulate taxa are usually also unitegmic and have a nucellar cap
(Philipson 1974). Bouman and Calis (1977) give details of the integuments of some Ranunculoideae. Z.-F. Wang and Ren (2008) suggested that unitegmic ovules have arisen in different ways, the single integument being either the outer (e.g. Clematis) or the inner integument (e.g. Ranunculus); they also described a rather obscure annular structure that surrounds the ovule in Coptis. The adaxial side of the carpels of Glaucidium grows more than the abaxial as the fruit develops, so the stigma ends up on the "lower" surface; there the embryo is shown
as being long by Tamura (1972) and Takhtajan (1988), but it is described as being minute by
Takhtajan (1997). There is extensive variation in embryo size (Tamura & Mizumoto 1972) and seedling morphology, and the development of a cotyledonary tube is quite common in the family, while Ranunculus ficaria, for example, has only a single cotyledon (Förster 1997).

Phylogeny. The clade [Hydrastis + Glaucidium] has been found to be
sister to the rest of the family by Hoot et al. (1998) and others since. This and other major phylogenetic structure within the family - [Coptoideae [Thalictroideae + Ranunculoideae]] - seems quite well established (c.f. also in part Ro et al. 1997; W. Wang et al. 2005). However, W. Wang et al. (2009) found strong molecular support for the relationships [Glaucidium [Hydrastis + rest of Ranunculaceae]], that for [Hydrastis + rest of Ranunculaceae] being weakened slightly by the addition of morphological data, while Soltis et al. (2011) found weak support for a topology [Hydrastis [Glaucidium + Ranunculus]] (only three taxa of Ranunculaceae in the analysis). Indeed, the vegetative and anatomical similarities between Glaucidium and Hydrastis are quite extensive, and if the two do not form a clade, using simply parsimony (ACCTRAN) one could argue that these would be apomorphies for the whole family... For other early work on the family, see Hoot (1991, 1995) and Jensen et al. (1995), and more recently, Cai et al. (2009, 2010).

For relationships within Thalictroideae, see Ro and McPheron (1997) and especially Wang and Chen (2007). Relationships along the spine of Thalictrum are for the most part poorly supported, but an insect-pollinated clade is sister to the rest; current sections seem largely useless (Soza et al. 2012).

Relationships around Ranunculus are interesting. Ficaria, Myosurus, with its very elongated receptacle and as a result a flower that looks like the inflorescence of Houttuynia (Saururaceae), and [Laccopetalum + Krapfia], with large to huge flowers, many carpels, polyporate pollen, an androgynophore, etc. (Lehnebach et al. 2007), are in a strongly supported clade with a monophyletic Ranunculus - see Hörandl et al. (2005), Paun et al. (2005), Hoot et al. (2008), Gehrke and Linder (2009: African montane taxa), and especially Emadzade et al. (2011). Hoot and Palmer (1994), Hoot et al. (1994), Hoot et al. (2004), Schuettpelz et al. (2002) and Meyer et al. (2010) discuss relationships in Anemone s.l., which includes Hepatica, Pulsatilla, etc.; there is a considerable amount of pollen variation in the clade (e.g. Ehrendorfer et al. 2009). However, Pfosser et al. (2011) suggests that Anemone may be best divided up into two, a clade having x = 7 (inc. Hepatica) and another with x = 8. For the phylogeny of Actaea, see Compton et al. (1998). Luo et al. (2005) discuss the phylogeny of Aconitum subgenus Aconitum. Jabbour and Renner (2011, 2012a) focused on the speciose Delphinieae, and the clades they found only partly mappped on to previously-recognized genera, while Aconitum gymnandrum, although belonging there, did not link with any major clade. There was little resolution of relationships within the speciose Delphinium section Diedropetala (Koontz et al. 2004). W. Wang et al. (2010) discuss relationships in Adonidae. Xie et al. (2011; see also Miikeda et al. 2006) provide a fairly comprehensive analysis of Clematis, unfortunately, several of the deeper branches in the genus are poorly supported, and the main clades that are evident neither correlate very well with previous infrageneric taxa nor have much morphological support.

Classification. The classification above is largely based on that in Tamura (1993). Glaucidium has quite often been placed in its own family (indeed, it was excluded from Ranunculaceae by Tamura), but it would be monotypic; although a distinctive plant, it has quite a lot in common with Hydrastis (see also Cai et al. 2010, c.f. in part Cai et al. 2009).

For generic limits around Ranunculus, see Emadzade et al. (2010), in Adonidae, see W. Wang et al. (2010), and aorund Anemone, see Pfosser et al. (2011). In the Delphinium area, Aconitella is derived from within Consolida, and the combined clade is to be included within Delphinium (Jabbour & Renner 2012; see also Jabbour et al. 2011). Actaea is to include Cimicifuga (Compton et al. 1998)

Previous Relationships. Ranunculaceae are a classic example
of a "famille par enchaînement", nothing in particular seeming to hold them together, but work over the last two decades suggests that they are largely monophyletic. However, Paeonia, quite often associated with Ranunculaceae in the past, is now included in Saxifragales as Paeoniaceae, while Tamura (1972) thought that Glaucidium was close to Hypericales.

Botanical Trivia. The zygote of Anemone flaccida is undivided at the time of seed dispersal (Tamura & Mizumoto 1972).